DOCSLIB.ORG

Petrology and Mineral Resources of the Wind Mountain Lagcolith, Cornudas

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Petrology and Mineral Resources of the Wind Mountain Lagcolith, Cornudas 335 The Carudian M iner alog ist Vol. 34, pp.33s-347(1,996) PETROLOGYAND MINERALRESOURCES OFTHE WIND MOUNTAIN LAGCOLITH, CORNUDASMOUNTAINS. NEW MEXICO AND TEXAS VIRGINIA T. McLEMORE. VIRGIL W. LT]ETH ANDTIM C. PBASE NewMeico Bureauof Minesand Mineral Resources, 801 l-eroy Place, Socorro, New Mertco 87801, U.SA. JAMES R. GTIILINGER AddwestMinerals, Inc., 546A Ward Roal, Suite370, Anada, Colorado80002, U.S.A. ABsrRAc"r The Wind Mountain laccolith is one of many intrusive bodiesfound in the CornudasMountains. These intrusive bodies comprisethe nortlern part of the Trans-Pecosalkaline magmaticprovince in southemNew Mexico and southwestemTexas. Ten laccoliths and stocks, along with numelous dikes, sills, and smaller plqs of varying textures,have infuded Permian limestoneand other sedimentaryrocks in the ComudasMountains axea. Nepheline syenite predominates, although phonolite, trachyte,and syenite are conmon The Wind Mountain laccolith is texturally and mineralogically zoned whereasthe other intrusivebodies in the ComudasMountains seem homogeneous. Wind Mountain consistsof two textural varietiesof nepheline syeniteporphyry and four textural varieties of syenite porphyry. The zonationis attributed to crystal fractionation, volatile separation,and cooling history, not to different pulsesofmagma. Feldsparcrystallization under initially hypersolvusconditions can accountfor most of the chemicalvariation in the volumetically lmger nephelinesyenite zones. Subsolvus conditions of feldspar crystallization,coupled with the separationof a volatile phase,was responsiblefor the chemical and mineralogical variation within the capping syenite units, which form a rind at the top of the pluton. The CornudasMountains have been examined for potential economic deposits of gold, silver, beryllium, rnre-eaxthelements, niobium, and uranium, but no production has occurred.The nephelinesyenite porphyry at Wind Mountain is being consideredas raw material for use in dark-coloredglass, flatglass, and ceramics. Keywords:Cornudas Mountains, 14'io4 146mtain Laccolith,nepheline syenite, syenite, alkaline rocks, New Mexico, Texas. Solvlulns The laccolite de Wind Mountain est un panni plusieurs massifs intrusifs affleurant dans les montagnesComudas, d I'extr6mit6nord de la provincemagmatique alcaline de Trans-Pecos,dans le sud du Nouveau-Mexiqueet le sud-ouestdu Texas. En tout dix laccoliteset plutons, ainsi que plusieursfilons, filons-coucheset petits massifsa texture variable recoupentles calcaireset autresroches s6dimentaires d'dge permien de la r6gion. La sydniten6ph6linique est pr6dominante,quoique la suite contient aussi phonolite, fachyte et sy6nite. l€ pluton de Wind Mountain, le plus imposant, est zon6 en texture et en min6ralogie,tandis que les autresmassifs intrusifs semblentplutdt homogbnes.Nous ddcrivonsdeux vari6t6stexturales de sy6nite ndphdliniqueporphyrique et quatre vari6t6s de sy6nite porphyrique. la zonation semble due d la cristallisation fractionn6e,la sdparationd'une phase volatile, et le taux variablede refroidissement,plut6t qu'i desvenues distinctes de magma. I,a crisrallisationde feldspathi desconditions tout d'abordhypersolws peut expliquerla plupart de la variation chimiqueparmi les diffdrentesvenues volumineuses de sy6nitendph6linique. les conditions propices d une cristallisation subsolws et d la s6parationd'une phase volatile rendentcompte des variations chimique et min6ralogiqueparrni les unit€ssup6rieures ale sy6nite, qui constituentune carapaceau sommetdu massif.La chalneCornudas a fait I'objet de recherchespour des anomaliesen or, axgent,b6ryllium, teres rares,niobium et uranirtm, mais sa:rsd6couvertes dignes d'exploitation.R6cemmenl on a initi6 un programmed'exploration et de d6veloppementde la sy6niten6ph6linique porphyrique pour sonpotentiel dans la fabricationde verre fonc6, velre en panneaux,et c6ramique;ce mat6riauaurait aussiun potentieldans la fabrication de granulespour toitures et d abrasifs,et dansI'industrie des pierres tai116es. (Traduil par la R6daction) Mots-cl6s: chalne de montagnesCornudas, laccolite de Wind Mountain, syenite n6phdlinique,sy6nite, roches alcalines, Nouveau-Mexique,Texas. 336 TIIE CANADIAN MINERALOGIST INTRoDUcnoN bodiesrepresent the northernexlent ofthe Trans-Pecos magmatic province. The Cornudas Mountains were Wind Mountain is one of ten Tertiary intrusive origrnally mapped in the early 1940s and 1950s as alkaline bodies that form the CornudasMountains in homogeneousplutons or laccoliths (Zapp 1941,Timm the Otero andDiablo plateausin soutlern New Mexico 1941,Clabaugh l94l,Warnet et al. 1959).Subsequent and southwestern Texas (Frg. 1). These intrusive petrological and geochemicalstudies along with JicarillaMountains @ @gapitan- a Mountains Qiena@ trtanca Orogrande I Une SeparatingAlkalic and Alkali-calcicFields a- \o, Trans-Pecos TexasMagmatlc Belt Mountains 0 50 | 00km llttl $ Big Bend Flc. l. Trans-Pecosmagmatis pl6yince, New Mexico and Texas(modified from Barker 1987,Price et al. 1.987).The inset nap showsthe Nor0r ArnericanCordilleran belt of alkaline igneousrocks (Woolley 1987,Mutschler et al. l99l). TT{E WIND MOT]NTAIN LACCOLITH. NEW ME)(ICO _ TEXAS 337 examinationof the Wind Mountain nephelinesyenite GEoLocIcALSrrrnqc by geologistsof Addwest Mnerals, Inc. revealedthat this unit is texfurally and mineralogically zoned Wind Mountain is one of ten larger sills, plugs, and (Mclemore & Guilinger 1993,Mclemore et aI. L994, laccoliths (Table 1, Fig. 2) and smallerdikes andplugs 199O. in the Cornudas Mountains that intrude relatively The purposeof this paper is to 1) summarizethe flat-lying limestone and other sedimentaryroctrs of petrology and mineralogy of the Wind Mountain the Hueco Limestone and Bone Spring Limestone laccolith, 2) describe the zones in the laccolith, @ermian).Other dikes, sills, and plugs are buried by 3) determinethe causeof zonation, and 4) describe sedimentarycover, as indicatedby subsurfacedrilling the mineral resourcepotential. (King & Harder 1985), geophysicalsurveys, and stuctural anomalies(i.e., anticlines,synclines, faults) REcIoNALSnrrr,ta in the overlying sedimentaryrocks. These intrusive bodiesvary in size from less than 700 m to 2.5 km in The Cornudas Mountains and the Trans-Pecos diameter.Wind Mountain is one of the largest@g. 2), magmatic province form part of the southern with a reported thickness of 0.25 km, an area of portion of the North American Cordilleran alkaline 4.3 ffi, and a minimum volumeof 1.1 km3 (Barker igneous belt. This belt is a diffrrse region of et a\.1977). Cenozoic igneous rocks tlat extends along the Barker et al. (1977) divided the fthologies found in eastern maryin of the North American Cordillera the Trans-Pecosmagmatic province into nine qpes on from Alaska and British Columbia southward into the basis of mineralogy and texture: 1) nepheline- Trans-PecosTexas and eastern Mexico (Fig. l; bearing augite syenite,2) nepheline-bearingtrachyte, Barker 1987,Mutschler et al. L985, 1991,Woolley 3) syenite, 4) nepheline syenite, 5) porphyritic r987). nephelinesyenite, 6) phonolite,7) foliated porphyritic The Trans-Pecosmagmatic province is a regional nepheline syenite, 8) quartz-bearing syenite, and belt of alkaline and metalumin6usigneous rocks that 9) quartz-bearingtrachyte. All nine types axefound in lie within an area defined by the Rio Grandeon the the Comudas Mountains; however, the predominzff west and south, the PecosRiver on the east, and an lithology is porphyritic nephelinesyenite. The largest east-westline approximately12 km north of the state laccoliths consistof dark gray to pink, fine- to coarse- boundary betweenNew Mexico and Texas (Frg. 1). gained equigranularto porphyritic nephelinesyenite. The province containsmore than 200 intusive bodies TABII 1. DESRIPNOTT OF IA\TBOUS INIRUSIVE BODIES having an outcroparea exceeding 1 km2(Barker 1977, tN TIIB OORNT'DAS MOUNIAINSI 1979, L987). The Trans-Pecosmagmatic province is the easternlimit of Cenozoic magmatic activity N@ Preddd R@ ASg in southwesternUnited Statesand Mexico. The mag- Iii.loly hlvta matism occurred in the region nearly continuously Al@ ph@Ute,btaled dtud@tde€t 36,810.6 B& a d. Agm, }I@t!h pGdrttfrc ls!frslhs 6 dn (K/Ar @ Ad@8lr(1941),9@y from 48 to 17 Ma @rjceet aI. 1987).Compositions of sydc hiodF) d aL (1916.) igneousrocks vary from alkalinein the easternportions Fl.al T@ Fs{!o, qldte f, Etu a at. (Ym, of the province, including the CornudasMountains, Mlcdah stldte dlb qab@!!091) to calc-alkalinewestward into Mexico (Fig. 1; Barker O@d6 phgqllmlih 34.6i1J Beds a aI. QYm, et al. L977 Barker& Hodges1977, Barker 1987, Price M@!to Itotu,E€4ff& (K/Ar@ @(1911),Estdaf , tEdn/to bioee) & Henry 1984,Cameron & Cameron1985,Pice et al. O98O 1987,Clark 1989). Wiid !@lhe sy€e. l@lih Btu a aL QCm, M@rh S@lllqDc@e W@€td. (1959), Early genetic interpretationssuggested an analogy llf'bgltoe ryld, fr&f@&Cdqq between the Trans-Pecosprovince and the Kenya 0993) portion of (Barker SeAdo nsddhecy@no I@&b TtBn (1941), the East African rift 1977). I\rl@lsh BM d el.(lrTD However, subsequentwork has shown that much of De6 *OlEta syrdb plogo la@lh 33.0t 1.4 Eatu d aL Qgm, the Cenozoic faulting in Trans-PecosTexas, earlier Mo@h Gl/Ar@ qabmsh(rg4r, P50), consideredto be associatedwith rifting, actually post- 0ltlel?id bto&e E@y 6 aI (lW lrlde) datesigneous activity @arker 1987,Henryet al. l99l). magmatic Cbaifeld d@lile dtl - Tno094l),8!rtE6t Trans-Pecos activity beganat the end of the lloqtrto d.Qqm Laramide compressionaltectonic period and may be Blar* lo(cryltrc !6!eelhe dll - Berts 4
Load more

Recommended publications
  • Feldspar and Nepheline Syenite 2016
    2016 Minerals Yearbook FELDSPAR AND NEPHELINE SYENITE [ADVANCE RELEASE] U.S. Department of the Interior January 2020 U.S. Geological Survey Feldspar and Nepheline Syenite By Arnold O. Tanner Domestic survey data and tables were prepared by Raymond I. Eldridge III, statistical assistant. In 2016, feldspar production in the United States was representing 46% of the 2016 production tonnages listed in estimated to be 470,000 metric tons (t) valued at $33.1 million, tables 1 and 2. an almost 10% decrease in quantity and a 11% decrease in Feldspar was mined in six States (table 3). North Carolina value compared with 2015 (table 1). Exports of feldspar in 2016 was by far the leading producer State; the remaining five were, decreased by 61% to 5,890 t, valued at $1.5 million, and imports in descending order of estimated output, Virginia, California, of feldspar decreased by 69% to 36,900 t, valued at $3.4 million. Idaho, Oklahoma, and South Dakota. Production was from Imports of nepheline syenite (predominantly from Canada) 10 mines and beneficiating facilities—4 in North Carolina, 2 in increased by 27% to about 572,000 t valued at $73 million. California, and 1 in each of the 4 remaining States (table 3). World production of feldspar in 2016 was 23.4 million metric I-Minerals Inc. continued the mine permitting process for tons (Mt) (tables 1, 7). its Helmer-Bovill project in north-central Idaho; the mine Feldspars, which constitute about 60% of the earth’s crust, would produce potassium feldspar, halloysite, kaolin, and are anhydrous aluminosilicate minerals of two main groupings: quartz.
    [Show full text]
  • Benefits of Utilizing Nepheline Syenite in Porcelain Tile
    1 BENEFITS OF UTILIZING NEPHELINE SYENITE IN PORCELAIN TILE AND SANITARYWARE Anais do 48º Congresso Brasileiro de Cerâmica Proceedings of the 48th Annual Meeting of the Brazilian Ceramic Society 28 de junho a 1º de julho de 2004 – Curitiba-PR SCOTT E. BARTON UNIMIN CORPORATION 500 WILSON PIKE CIRCLE, SUITE 127 BRENTWOOD, TENNESSEE 37027 USA EXECUTIVE SUMMARY Nepheline syenite is a commercially prepared, rare feldspathoid-rich rock product that contributes both potassium and sodium oxides to the ceramic formulation. It has been used in both North America and Europe for the production of porcelain tile and sanitaryware for many years. It is the unique mineralogy and high levels of alkalis of nepheline syenite that justify its use in ceramics. These characteristics promote lower firing temperatures that can enhance productivity and lower production costs. Depending on location, the use of nepheline syenite can lower raw material cost by allowing more silica to be used in the formulation. Additionally, the process control found in most nepheline syenite operations offers a controlled level of Fe2O3 that can help to improve fired color. The goal of this study is to illustrate the practical benefits of using nepheline syenite for the vitrification in a ceramic body formulation. Keywords: nepheline syenite, porcelain, tile, feldspar, sanitaryware INTRODUCTION As the porcelain tile and sanitaryware industries continue to globalize, manufacturers must continually improve the control and quality of their raw materials to effectively compete on the global scale. To do so, many manufacturers must look not only at domestic materials but also at external sources for these important requirements of quality and consistency.
    [Show full text]
  • Multiple Processes of Geochemical Evolution for the Alkaline Rocks Of
    213213 https://doi.org/10.11606/issn.2316-9095.v20-151049 Revista do Instituto de Geociências - USP Geol. USP, Sér. cient., São Paulo, v. 20, n. 4, p. 221-214, Dezembro 2020 Multiple processes of geochemical evolution for the alkaline rocks of Rio Bonito intrusive complex, Rio de Janeiro State, Brazil: 40Ar/39Ar and U-Pb ages and Lu-Hf isotopes on zircon and constraints on crustal signature Múltiplos processos de evolução geoquímica para as rochas alcalinas do complexo intrusivo de Rio Bonito, Estado do Rio de Janeiro, Brasil: idades 40Ar/39Ar e U-Pb e isótopos Lu-Hf em zircão – considerações sobre assinatura crustal Daniel Adelino da Silva1 , Akihisa Motoki1Ϯ, Anderson Costa dos Santos1 , Julio Mendes2 , Fred Jourdan3 , Mauro César Geraldes1 , Cristiano de Carvalho Lana4 2Universidade do Estado do Rio de Janeiro - UERJ, Departamento de Mineralogia e Petrologia Ígnea, Rua São Francisco Xavier, 524, CEP 20550-900, Rio de Janeiro, RJ, BR ([email protected]; [email protected]; [email protected]); Ϯin memoriam. 2Universidade Federal do Rio de Janeiro - UFRJ, Instituto de Geociências, Rio de Janeiro, RJ, BR ([email protected]) 1University of Technology - GPO, Western Australian Argon Isotope Facility, Department of Applied Geology & JdL Centre, Curtin, Perth, Australia ([email protected]) 4Universidade Federal de Ouro Preto - UFOP, Isotope Geochemistry Laboratory, Ouro Preto, MG, BR ([email protected]) Received on October 22, 2028; accepted on November 6, 2020 Abstract This article presents geochemical characteristics of the alkaline rocks of Rio Bonito intrusive complex, State of Rio de Janeiro, Brazil, which is constituted mainly by nepheline syenite.
    [Show full text]
  • Rare Earth Element Mobility During Conversion of Nepheline Syenite Into Lateritic Bauxite at Passa Quatro, Minais Gerais, Brazil B
    Applied Geochemistry, Vol. 9, pp. 701-711,1994 Pergamon Copyright 01994 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0883-2927/94 $7.00+0.00 0883-2927(94)E0025-5 Rare earth element mobility during conversion of nepheline syenite into lateritic bauxite at Passa Quatro, Minais Gerais, Brazil B. BOULANGÉand F. COLÌN- ORSTOM, UM GECO, Laboratoire de Géosciences de l’Environnement, Université Aix Marseille III, 13397 Marseille CBdex 20, France (Received 10 July 1992; accepted in revised form 4 May 1994) Abstract-In a lateritic bauxite formed by weathering of nepheline syenite at Passa Quatro, Minas Gerais State, Brazil, bauxites on the hill-tops directly develop from the syenite bed-rock, while downslope, a kaolinitic layer occurs between bauxite and syenite. A petrological investigation was performed on undisturbed weathered rock samples collected from a representative upslope pit. The undisturbed weathered rocks were chemically analysed for major and trace elements including REE and Zr. Mass balance calculations were applied, and the behaviour of the REE in the Passa Quatro weathering system was established compared to REE reference chondrite and to REE reference parent rock. In the lateritic bauxite, the results suggest that the first stages of weathering induce a volumetric change of 50%, i.e. collapse, with respect to the parent rock, and remove REE with a slightly larger loss of the LREE, except Ce, compared to the HREE. In the upper layers, where bauxite is more mature, a net mass gain in REE is observed relative to the underlying layers. This gain takes place during the reduction of the upper layer during the downward progression of the weathering front.
    [Show full text]
  • Petro-Geochemistry, Genesis and Economic Aspect of Syenitic and Mafic Rocks in Mindif Complex, Far North Cameroon, Central Africa
    International Journal of Geosciences, 2019, 10, 1081-1114 https://www.scirp.org/journal/ijg ISSN Online: 2156-8367 ISSN Print: 2156-8359 Petro-Geochemistry, Genesis and Economic Aspect of Syenitic and Mafic Rocks in Mindif Complex, Far North Cameroon, Central Africa Nguo Sylvestre Kanouo1*, Lianxun Wang2, Arnaud Patrice Kouske3, Syprien Bovari Yomeun2, Emmanuel Archelaus Afanga Basua2 1Mineral Exploration and Ore Genesis Unit, Department of Mining Engineering and Mineral Processing, Faculty of Mines and Petroleum Industries, University of Maroua, Maroua, Cameroon 2School of Earth Sciences, China University of Geosciences, Wuhan, China 3Department of Civil Engineering, The University Institute of Technology, University of Douala, Douala, Cameroon How to cite this paper: Kanouo, N.S., Abstract Wang, L., Kouske, A.P., Yomeun, S.B. and Basua, E.A.A. (2019) Petro-Geochemistry, Syenitic and mafic rocks in Mindif Complex (Far North of Cameroon) were Genesis and Economic Aspect of Syenitic surveyed and characterized to classify them, understand their formation his- and Mafic Rocks in Mindif Complex, Far tory, and assess their economic interest. Syenitic bodies (hololeucocratic North Cameroon, Central Africa. Interna- tional Journal of Geosciences, 10, 1081-1114. microsyenites; mesocratic aplitic quartz-syenite; leucocratic porphyritic https://doi.org/10.4236/ijg.2019.1012062 quartz-biotite syenite, and leucocratic porphyritic biotite-syenite) are sili- ca-oversaturated to silica-saturated, alkaline, and metaluminous. Hololeu- Received: June 16, 2019 cocratic microsyenites are structural oriented rocks, cooled in shallow Accepted: December 6, 2019 Published: December 9, 2019 depth from low trace and REE dry residual alkaline melts. Mesocratic ap- litic quartz-syenite also crystallized in shallow depth from a much Ba-rich Copyright © 2019 by author(s) and less dry residual melt.
    [Show full text]
  • Nepheline Syenite from Lyle Lake, Peter Lake Domain (NTS 64E-06) 1
    Nepheline Syenite from Lyle Lake, Peter Lake Domain (NTS 64E-06) 1 David H. Quiff Quirt, D.H. (1992): Nepheline syenite from Lyle Lake, Peter Lake Domain (NTS 64E-06); in Summary of Investigations 1992, Sas­ katchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 92-4. The Peter Lake Domain nepheline and nepheline-biotite­ The region has been geologically mapped by the Sas­ sodalite syenite occurrence located at Lyle Lake, Sas­ katchewan Geological Survey at 1:50 CXX> scale (Lewry, katchewan (NTS 64E-06; UTM 613000E 6366000N; Fig­ 1976; Lewry et al., 1980); the Lyle Lake area being ure 1) is the only known example of silica-under­ mapped as metadiorite and monzonite with syenite. saturated felsic magmatism in Saskatchewan. This MacDougall (1987) mapped the region immediately report presents new geological, petrological, and south of Lyle Lake at 1:20 000 scale. The nepheline mineralogical data about these rocks. syenite occurrence was discovered in 1982 during the course of off-property mineral exploration by the Sas­ katchewan Mining and Develop­ ment Corporation (now Cameco; Wittrup, 1983; Waterman et al., 1984). MacDougall (1987) briefly noted the presence of under­ saturated rocks in the Lyle Lake area. The nepheline syenite is found near the Lyle Lake pluton, a Hud­ sonian post-deformational granitic intrusion (MacDougall, 1987) ATHABASCA BASIN situated within the Archean Peter Lake Domain close to the bound­ 58' ary with the Hudsonian Wathaman / ,,,. ; Batholith. The Peter Lake Domain ' consists of massive to weakly foliated felsic plutonic rocks and a diorite-gabbroic plutonic suite which together have a complex Ar­ chean intrusion history (Lewry er al., 1980; Ray and Wanless, 1980; Annesley et al., 1992).
    [Show full text]
  • The Red Syenite of the Pilanesberg Complex As a Nepheline Source for the South African Ceramics and Glass Industry
    University of Pretoria etd Pantshi B 2006 The Red Syenite of the Pilanesberg Complex as a nepheline source for the South African ceramics and glass industry. By Bukiwe Pantshi Submitted in partial fulfilment of the requirements For the MSc in Earth Science Practice and Management In the Faculty of Natural and Agricultural Sciences. University of Pretoria March 2006 University of Pretoria etd Pantshi B 2006 CONTENTS Page ABSTRACT 5 1. INTRODUCTION 6 1.1. Statement of question 6 1.2. The hypothesis 7 1.3. Assumptions 7 1.4. Purpose of the study 7 1.5. Acknowledgements 8 2. REVIEW OF RELATED LITERATURE 9 2.1. Geology of the Pilanesberg Complex 9 2.1.1. Red Foyaite 11 2.1.2. White & Grey Foyaite 12 2.1.3. Tinguaite 13 2.1.4. Green Foyaite 13 2.1.5. Ledig Foyaite 14 2.1.6. Red Syenite 14 2.1.7. Volcanic rocks 15 2.2. Age of the plutonic rocks 15 2.3. Mineral potential of the Pilanesberg 16 2.3.1. Gold 16 2.3.2. Rare earth Elements 16 2.3.3. Dimension Stone 17 3. GENERAL DISCUSSION OF NEPHELINE AND ASSOCIATED DEPOSITS 18 3.1. Characteristics of nepheline 18 3.2. Classification of nepheline syenite ore deposits 19 3.3. Distribution of nepheline syenite deposits 19 3.3.1. Two deposits described for beneficiation 21 3.3.1.1. Table Mountain Deposit, Oregon 21 3.3.1.2. Bulls Run Syenite Complex, South Africa 22 3.4. Evaluation of raw material required in ceramics and glass 22 3.4.1.
    [Show full text]
  • Crystallization and Metasomatism of Nepheline Syenite Xenoliths in Quartz-Bearing Intrusive Rocks in the Permian Oslo Rift, SE Norway
    Crystallization and metasomatism of nepheline syenite xenoliths in quartz-bearing intrusive rocks in the Permian Oslo rift, SE Norway TOM ANDERSEN & HENNING SØRENSEN Andersen, T. & Sørensen, H.: Crystallization and metasomatism of nepheline syenite xenoliths in quartz-bearing intrusive rocks in the Permian Oslo rift, SE Norway. Norsk Geologisk Tidsskrift, Vol. 73, pp. 250-266. Oslo 1993. ISSN 0029-196X. Small bodies of metasomatized nepheline syenite occur as xenoliths in syenitic and granitic intrusions in the Mykle area, ca. 30 km N of the Larvik pluton in the Vestfold Graben of the late Paleozoic Qslo rift of SE Norway. The nepheline syenite has a metaluminous major element composition, and its primary igneous mineralogy is: alkali feldspar + nepheline + clinopyroxene + titanite + magnetite + apatite ± amphibole. The mafic silicate minerals have lower (Na + K)/AI than comparable minerals in other fe lsic intrusions in the Oslo Rift. Gamet (grossular-andradite), analcime, sodalite, thomsonite and gonnardite occur as interstitial minerals in the )east altered parts of the nepheline syenite. The xenoliths were metasomatized as a result of interaction between nepheline syenite and younger silica-saturated to oversaturated magrnas and their associated fluids. Early, pervasive metasomatism led to breakdown of nepheline, replacement of pyroxene by biotite ± garnet and crystallization of quartz. Recrystallization took place at solidus-near temperatures (700-725°C), and was controlled by an increase in silica activity and oxygen fugacity. Titanite + magnetite were replaced by rutile + quartz + hematite + calcite at a late stage of the metasomatic history, at oxygen fugacities above the HM buffer, and T < 450°C. The xenoliths indicate the former presence of larger bodies of nepheline syenite in an area where no such rocks were known previously.
    [Show full text]
  • Petrogenesis and Tectonic Implications of Peralkaline A-Type Granites and Syenites from the Suizhou-Zaoyang Region, Central China
    Journal of Earth Science, Vol. 29, No. 5, p. 1181–1202, October 2018 ISSN 1674-487X Printed in China https://doi.org/10.1007/s12583-018-0877-2 Petrogenesis and Tectonic Implications of Peralkaline A-Type Granites and Syenites from the Suizhou-Zaoyang Region, Central China Hafizullah Abba Ahmed 1, 2, Changqian Ma *1, Lianxun Wang1, Ladislav A. Palinkaš3, Musa Bala Girei1, 4, Yuxiang Zhu1, Mukhtar Habib5 1. State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China 2. Department of Geology, Modibbo Adama University of Technology, Yola P.M.B. 2076, Nigeria 3. Institute of Mineralogy and Petrology, Faculty of Sciences, University of Zagreb, Zagreb HR-10000, Croatia 4. Department of Geology, Faculty of Earth and Environmental Sciences, Bayero University, Kano, Nigeria 5. Department of Mineral and Petroleum Resources Engineering, Kaduna Polytechnic, Kaduna, Nigeria Hafizullah Abba Ahmed: https://orcid.org/0000-0002-6679-4427; Changqian Ma: https://orcid.org/0000-0002-1778-0547 ABSTRACT: In this study, we present systematic petrological, geochemical, LA-ICP-MS zircon U-Pb ages and Nd isotopic data for the A-type granites and syenites from Suizhou-Zaoyang region. The results show that the peralkaline A-type granites and syenites were episodically emplaced in Suizhou-Zaoyang region between 450±3 and 441±7 Ma which corresponds to Late Ordovician and Early Silurian periods, respec- tively. Petrologically, the syenite-peralkaline granite association comprises of nepheline normative-syenite and alkaline granite in Guanzishan and quartz normative syenite and alkaline granite in Huangyangshan. The syenite-granite associations are ferroan to alkali in composition.
    [Show full text]
  • Alkaline Rock Complexes in the Wet Mountains Area, Custer and Fremont Counties, Colorado
    Alkaline Rock Complexes in the Wet Mountains Area, Custer and Fremont Counties, Colorado GEOLOGICAL SURVEY PROFESSIONAL PAPER 1269 Alkaline Rock Complexes in the Wet Mountains Area, Custer and Fremont Counties, Colorado By THEODORE J. ARMBRUSTMACHER GEOLOGICAL SURVEY PROFESSIONAL PAPER 1269 Geology and petrology of rocks of the McClure Mountain Complex, Gem Park Complex, and complex at Democrat Creek and associated alkaline rocks UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1984 UNITED STATES DEPARTMENT OF THE INTERIOR WILLIAM P. CLARK, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director Library of Congress Cataloging in Publication Data Armbrustmacher, Theodore J., 1946- Alkaline Rock complexes in the Wet Mountains area, Custer and Fremont Counties, Colorado. (Geological Survey Professional Paper 1269) Bibliography: 33 p. Supt. of Docs. No.: 119.16:1269 1. Alkalic igneous rocks. 2. Petrology Colorado Wet Mountains. I. Title. II. Series. QE462.A4A76 552'.3 82-600104 AACR2 CONTENTS Abstract ............................. 1 Ages of the complexes ..................... 14 Introduction ........................... 1 Geochemistry ........................... 15 Acknowledgments ........................ 1 Major elements ....................... 15 Geologic setting ......................... 2 Mafic-ultramafic rocks ................. 15 McClure Mountain Complex .................. 2 Leucocratic rocks ................... 16 Mafic-ultramafic rocks ................... 2 Mafic nepheline-clinopyroxene rocks ......... 19 Layered series ....................
    [Show full text]
  • The Origin of Hydrocarbon Gases in the Lovozero Nepheline-Syenite Massif (Kola Peninsula, NW Russia), As Revealed from He and Ar Isotope Evidence
    minerals Article The Origin of Hydrocarbon Gases in the Lovozero Nepheline-Syenite Massif (Kola Peninsula, NW Russia), as Revealed from He and Ar Isotope Evidence Valentin Nivin Geological Institute, Kola Science Centre, Russian Academy of Sciences, 14 Fersman St., 184209 Apatity, Russia; [email protected]; Tel.: +7-815-55-79-580 Received: 15 August 2020; Accepted: 16 September 2020; Published: 21 September 2020 Abstract: The occurrence of hydrocarbon gases (HCG) in unusually high concentrations for magmatic complexes, in the Lovozero and some other alkaline massifs, is of both geochemical and practical interest. The nature of these gases, despite the long history of research, remains the subject of debate. As an approach to solving this problem, we studied the coupled distribution of occluded HCG and the recognized tracers of various geological processes, such as helium and argon isotopes. The extraction of the gas components trapped in fluid micro-inclusions was carried out by the mechanical crushing 3 4 of rock and mineral samples. A positive correlation was found between the He/ He and CH4/C2H6 ratios, whereas a negative correlation of the latter was found with the 36Ar concentration, which in turn was directly related, in varying degrees, to the content of HCG and most strongly with pentanes. Conjugacy of the processes of the heavier gaseous hydrocarbons, a loss of the deep component of the fluid phase and dilution of it with the atmogenic component was established. In the absence of a 3 3 correlation between CH4 and He, the value of the CH4/ He ratio in the Lovozero gas substantially exceeded the estimates of it in gases of a mantle origin, and mainly corresponded to the crustal values.
    [Show full text]
  • Mineral Commodity Summaries 2016 U.S
    MINERAL COMMODITY SUMMARIES 2016 U.S. Department of the Interior U.S. Geological Survey MINERAL COMMODITY SUMMARIES 2016 Abrasives Fluorspar Mercury Silicon Aluminum Gallium Mica Silver Antimony Garnet Molybdenum Soda Ash Arsenic Gemstones Nickel Stone Asbestos Germanium Niobium Strontium Barite Gold Nitrogen Sulfur Bauxite Graphite Palladium Talc Beryllium Gypsum Peat Tantalum Bismuth Hafnium Perlite Tellurium Boron Helium Phosphate Rock Thallium Bromine Indium Platinum Thorium Cadmium Iodine Potash Tin Cement Iron and Steel Pumice Titanium Cesium Iron Ore Quartz Crystal Tungsten Chromium Iron Oxide Pigments Rare Earths Vanadium Clays Kyanite Rhenium Vermiculite Cobalt Lead Rubidium Wollastonite Copper Lime Salt Yttrium Diamond Lithium Sand and Gravel Zeolites Diatomite Magnesium Scandium Zinc Feldspar Manganese Selenium Zirconium U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Director U.S. Geological Survey, Reston, Virginia: 2016 Manuscript approved for publication January 28, 2016. For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment— visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod For sale by the Superintendent of Documents, U.S. Government Publishing Office Mail: Stop IDCC; Washington, DC 20402–0001 Phone: (866) 512–1800 (toll-free); (202) 512–1800 (DC area) Fax: (202) 512–2104 Internet: bookstore.gpo.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted material contained within this report.
    [Show full text]